For decades, stamp-collecting was the hobby of kings - George V having been such a fan that he spent most of his reign in the royal stamp room. But in the last few decades, the hobby's popularity has stalled so much that the current crop of avid philatelists worry that when they die, so will the pastime. If there's anyone who can convince of the obsession-inducing delights of the stamp, it's Simon Garfield, who perceptively traces how his schoolboy enthusiasm exploded into a huge, secret passion around the time his marriage collapsed. It's a rather melancholy story, though, as stamp collecting comes at a cost and not just the financial one: no matter how much money and time one spends, one's collection will never be complete.